Interconnection structure of photovoltaic module
By adopting a parallel cell string and grouped main grid design in photovoltaic modules, two parallel current paths are formed, and the PN junction of the cells automatically redirects the current, solving the problems of current path rigidity and thermal hazards, improving the reliability and power generation efficiency of the modules, simplifying the design and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 江苏海博瑞光伏科技有限公司
- Filing Date
- 2025-05-19
- Publication Date
- 2026-05-19
AI Technical Summary
Existing photovoltaic modules suffer from reduced reliability and efficiency due to rigid current paths, thermal hazards, and busbar overload issues under shading or uneven shading conditions. Furthermore, the reliance on bypass diodes increases costs and the risk of failure.
It adopts a parallel battery string and grouped main grid line design, and forms two parallel current paths by connecting them through series busbars. It also utilizes the PN junction of the battery cells to achieve automatic current redirection, reduce current concentration, and uses thickened low-resistance interconnect bars and bypass diodes.
It improves current shunting flexibility, reduces thermal risks, simplifies design and reduces costs, and enhances the reliability and power generation efficiency of photovoltaic modules.
Smart Images
Figure CN224265393U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of photovoltaic module technology, and in particular relates to an interconnection structure for photovoltaic modules. Background Technology
[0002] The key component of a photovoltaic module is the solar cell, in which current is connected through multiple main grid lines. The cells are connected in series to form a cell string by welding ribbons (interconnecting strips) to each main grid line. Typically, the output current of the cell string is combined in parallel through the connecting ribbons (busbars) between the cells.
[0003] In practical applications, when photovoltaic modules are shaded or partially damaged, existing technologies often use parallel connection of multiple series-connected battery strings to cope with partial shading or asymmetrical current flow, and use bypass diodes in the parallel busbar to avoid the influence of reverse current or unbalanced current. The advantage of this solution is that it has a simple structure and can prevent current backflow when there is partial shading or cell failure, thereby improving the stability of the system.
[0004] However, the existing solutions have the following shortcomings:
[0005] 1. Current path rigidity and potential thermal hazards: In traditional multi-busbar connection design, all the busbars of a battery string are usually connected to the same adjacent battery string as a whole. This causes the current generated by the battery string to flow in only one direction. When there is local shading or uneven performance, there is a lack of redundancy and regulation capability of the current path. The current is concentrated in a specific path, which not only aggravates the local thermal risk, but also reduces the overall reliability and energy output efficiency of the module.
[0006] 2. Busbar overload: In existing solutions, the solder strips of multiple battery strings are usually gathered on a wide and thick busbar to carry large current. Although this design can handle high current, hot spots are easily generated at the busbar under local shading or mismatch conditions, which leads to an increase in the temperature of the battery string, thereby affecting the power generation efficiency and reducing the reliability of the module.
[0007] 3. Reliance on bypass diodes: Traditional solutions require additional bypass diodes to prevent reverse current, increasing costs and failure risks. Utility Model Content
[0008] The purpose of this utility model is to provide an interconnection structure for photovoltaic modules to solve the problems in the prior art. The specific technical solution is as follows:
[0009] An interconnection structure for a photovoltaic module includes a first battery string, a second battery string, and a third battery string arranged in parallel. The second battery string is connected to the first battery string via a series busbar one, and the second battery string is connected to the third battery string via a series busbar two.
[0010] Furthermore, the first, second, and third battery strings are all composed of multiple battery cells connected in series. Each battery cell is provided with multiple main grid lines, which are grouped into G1 grid lines and G2 grid lines by a central symmetry line.
[0011] Furthermore, the G1 group grid lines of the second battery string are connected to the G2 group grid lines of the first battery string through a series bus bar one, and the G2 group grid lines of the second battery string are connected to the G1 group grid lines of the third battery string through a series bus bar two.
[0012] Furthermore, in the first battery string, the main grid line near the center of the cell in the G2 group of grid lines is connected to the first series busbar to form a left-end interconnection bar, and in the third battery string, the main grid line near the center of the cell in the G1 group of grid lines is connected to the second series busbar to form a right-end interconnection bar.
[0013] Furthermore, both the left and right interconnecting strips are thickened, with a thickness ≥0.30mm.
[0014] Furthermore, both the left and right interconnecting strips are made of low-resistance material with a resistance ≤0.0177Ωmm. 2 / m.
[0015] Furthermore, a PN junction is provided between the G1 group gate lines and the G2 group gate lines. The PN junction isolates the G1 group gate lines and the G2 group gate lines in parallel, forming two equivalent parallel current paths, namely the G1 group gate line path and the G2 group gate line path.
[0016] Furthermore, the G1 group of grid lines is blocked, and the current is automatically redirected to the low-resistance G2 group of grid lines through the built-in electric field of the PN junction inside the cell.
[0017] The advantages of this utility model are:
[0018] 1. Improve current shunting flexibility and reduce thermal risks: By grouping the main grid lines and connecting them to two adjacent battery strings on the left and right, two parallel current paths are formed, which allows the current inside the battery string to be automatically shunted to the low-resistance path according to the shading situation, fundamentally alleviating the problem of heat accumulation caused by current concentration.
[0019] 2. Reduce bus load and optimize current distribution: Since the current has been diverted to multiple directions inside the battery string, the current density at a single bus point is effectively reduced, reducing the risk of local overheating caused by large current passing through a single point, which helps to miniaturize the bus structure and improve its thermal stability.
[0020] 3. Parallel isolation is achieved by utilizing the PN junction characteristics of the solar cell. The two equivalent parallel current paths within the series do not require bypass diodes, simplifying the design and reducing costs. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the battery cell stacking of this utility model;
[0022] Figure 2 for Figure 1 Enlarged view of a portion of point A in the middle;
[0023] Figure 3 for Figure 1 Enlarged view of a section at point B in the middle;
[0024] Figure 4 This is a circuit diagram of the present invention;
[0025] Explanation of markings in the diagram:
[0026] First battery string 1; Second battery string 2; Third battery string 3; Series bus bar 1 4; Series bus bar 2 5; Left end interconnection bar 6; Right end interconnection bar 7. Detailed Implementation
[0027] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0029] Example 1
[0030] like Figure 1-4 As shown, an interconnection structure of a photovoltaic module includes a first battery string 1, a second battery string 2 and a third battery string 3 arranged in parallel. The second battery string 2 is connected to the first battery string 1 through a series bus bar 4, and the second battery string 2 is connected to the third battery string 3 through a series bus bar 5.
[0031] The working principle of the above technical solution is as follows: the second battery string 2 is connected to the first battery string 1 through the series bus bar 4, and the second battery string 2 is connected to the third battery string 3 through the series bus bar 5. The main grid lines in the second battery string 2 are grouped and connected to the two adjacent battery strings on the left and right respectively, forming two parallel current paths. This allows the current inside the battery string to be automatically diverted to the low resistance path according to the blocking situation, which fundamentally alleviates the problem of heat accumulation caused by current concentration.
[0032] Since the current is diverted to multiple directions inside the battery string, the current density at a single busbar is effectively reduced, which reduces the risk of local overheating caused by a large current passing through a single point and helps to miniaturize the busbar structure and improve its thermal stability.
[0033] Example 2
[0034] like Figure 1-4 As shown, the first battery string 1, the second battery string 2 and the third battery string 3 are all composed of multiple battery cells connected in series. Each battery cell is provided with multiple main grid lines. The multiple main grid lines are grouped into G1 group grid lines and G2 group grid lines by a central symmetry line.
[0035] The G1 group grid lines of the second battery string 2 are connected to the G2 group grid lines of the first battery string 1 through a series bus bar 4, and the G2 group grid lines of the second battery string 2 are connected to the G1 group grid lines of the third battery string 3 through a series bus bar 5.
[0036] The working principle of the above technical solution is as follows: The G1 group grid lines of the second battery string 2 are connected to the G2 group grid lines of the first battery string 1 through the series bus bar 4, forming the first current path. The G2 group grid lines of the second battery string 2 are connected to the G1 group grid lines of the third battery string 3 through the series bus bar 5, forming the second current path. When the first current path is blocked, the current automatically turns to the low-resistance second current path through the built-in electric field of the PN junction in the battery cell, reducing the heat accumulation in the first current path.
[0037] Example 3
[0038] like Figure 1-4 As shown, in the first battery string 1, the main grid line near the center of the battery cell in the G2 group grid line is connected to the series bus bar 4 to form the left end interconnection bar 6, and in the third battery string 3, the main grid line near the center of the battery cell in the G1 group grid line is connected to the series bus bar 5 to form the right end interconnection bar 7.
[0039] Both the left-end interconnecting strip 6 and the right-end interconnecting strip 7 are thickened, with a thickness ≥ 0.30 mm;
[0040] Both the left-end interconnecting strip 6 and the right-end interconnecting strip 7 are made of low-resistance material with a resistance ≤ 0.0177 Ωmm.2 / m;
[0041] The working principle of the above technical solution is to ensure that when a certain path is blocked, a low-resistance path can be effectively provided for the current.
[0042] Example 4
[0043] like Figure 1-4 As shown, a PN junction is provided between the G1 group gate lines and the G2 group gate lines. The PN junction isolates the G1 group gate lines and the G2 group gate lines in parallel, forming two equivalent parallel current paths, namely the G1 group gate line path and the G2 group gate line path.
[0044] The G1 grid line path is blocked, and the current is automatically redirected to the low-resistance G2 grid line path through the built-in electric field of the PN junction in the cell.
[0045] The working principle of the above technical solution is as follows: When the G1 group grid line path is blocked, the current automatically redirects to the low-resistance G2 group grid line path through the built-in electric field of the PN junction in the cell. When the G2 group grid line path is blocked, the current automatically redirects to the low-resistance G1 group grid line path through the built-in electric field of the PN junction in the cell. This adaptive mechanism fundamentally alleviates the heat accumulation problem caused by current concentration and effectively reduces the current density at a single busbar point, reducing the risk of local overheating caused by large current passing through a single point. This contributes to the miniaturization and thermal stability improvement of the busbar structure.
[0046] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.
Claims
1. An interconnection structure of a photovoltaic module, characterized by, It includes a first battery string (1), a second battery string (2) and a third battery string (3) arranged in parallel. The second battery string (2) is connected to the first battery string (1) through a series bus bar one (4), and the second battery string (2) is connected to the third battery string (3) through a series bus bar two (5).
2. An interconnection structure for a photovoltaic module according to claim 1, wherein The first battery string (1), the second battery string (2) and the third battery string (3) are all composed of multiple battery cells connected in series. Each battery cell is provided with multiple main grid lines. The multiple main grid lines are grouped into G1 grid lines and G2 grid lines by a central symmetry line.
3. An interconnection structure for a photovoltaic module according to claim 2, wherein The G1 grid line of the second battery string (2) is connected to the G2 grid line of the first battery string (1) through a series bus bar one (4), and the G2 grid line of the second battery string (2) is connected to the G1 grid line of the third battery string (3) through a series bus bar two (5).
4. An interconnection structure for a photovoltaic module according to claim 3, wherein In the first battery string (1), the main grid line near the center of the battery cell in the G2 group grid line is connected to the series bus bar one (4) to form the left end interconnection bar (6), and in the third battery string (3), the main grid line near the center of the battery cell in the G1 group grid line is connected to the series bus bar two (5) to form the right end interconnection bar (7).
5. An interconnection structure for a photovoltaic module according to claim 4, wherein Both the left-end interconnecting strip (6) and the right-end interconnecting strip (7) are thickened, with a thickness ≥ 0.30 mm.
6. An interconnection structure for a photovoltaic module according to claim 5, wherein The left end interconnecting strip (6) and the right end interconnecting strip (7) both use low-resistance material, whose resistance is ≤0.0177 Ωmm 2 / m.
7. An interconnection structure for a photovoltaic module according to claim 6, wherein A PN junction is provided between the G1 group gate lines and the G2 group gate lines. The PN junction isolates the G1 group gate lines and the G2 group gate lines in parallel, forming two equivalent parallel current paths, namely the G1 group gate line path and the G2 group gate line path.
8. An interconnection structure for a photovoltaic module according to claim 7, wherein When the G1 grid line path is blocked, the current is automatically redirected to the low-resistance G2 grid line path through the built-in electric field of the PN junction inside the cell.